#app-container {
  display: flex;
  width: 100%;
  height: 100%;
  background: var(--bg-main);
  padding: 20px;
  gap: 20px;
}

/* Base styles for the 3 columns */
.sidebar-left,
.chat-center,
.sidebar-right {
  background: var(--surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: all 0.3s ease;
}

/* 1. Left Sidebar: Rooms List */
.sidebar-left {
  width: 320px;
  flex-shrink: 0;
  background: var(--bg-sidebar);
}

/* 2. Center: Chat Area */
.chat-center {
  flex: 1;
  background: var(--bg-chat);
  box-shadow: none;
  position: relative;
}

/* 3. Right Sidebar: Details */
.sidebar-right {
  width: 300px;
  flex-shrink: 0;
  background: var(--bg-details);
}

/* Responsive */
@media (max-width: 1100px) {
  .sidebar-right {
    display: none; /* Hide details on medium screens */
  }
}

@media (max-width: 768px) {
  #app-container {
    padding: 0;
    gap: 0;
  }
  .sidebar-left,
  .chat-center,
  .sidebar-right {
    border-radius: 0;
  }
  
  /* Mobile approach: only show one view at a time */
  body[data-view="rooms"] .chat-center { display: none; }
  body[data-view="chat"] .sidebar-left { display: none; }
  
  .sidebar-left { width: 100%; }
}

/* Utility to hide/show views */
.hidden { display: none !important; }